Justice Hall said Ugle had been caught in a vicious cycle whereby she abused drugs, including injecting methamphetamine, in an attempt to cope with her mental illness but it made it worse.

She had been diagnosed with paranoid schizophrenia but was untreated in the lead-up to the killing.

Justice Hall said her mental illness was one but not the only cause of the attack and it reduced her culpability to some extent.

However, she had been able to rationalise and bid for a better outcome for herself when police told her - as Jamahl was clinging to life in hospital - that she would be charged with attempted murder, arguing she should instead be charged with unlawful wounding.

"I didn't stab him that bad," she told the officers.

"He wasn't bleeding much after I cut him."

Ugle, who has two other children, will be eligible for parole in May 2021 after she has served four years and six months, considering she has been in jail since the crime.

When Justice Hall handed down the sentence on Friday, family members sobbed and shouted in anger.